Biocoke producing apparatus and process therefor

ABSTRACT

A biocoke producing apparatus that realizes efficient mass production of biocoke; and a process therefor. There is disclosed a biocoke producing apparatus capable of pressure molding of a moisture-regulated pulverized biomass while heating the same in a reaction vessel ( 1 ) to thereby obtain biocoke. In the reaction vessel ( 1 ), there are preset the temperature range and pressure range for, without carbonizing of the pulverized biomass, inducing a pyrolytic or thermal curing reaction of lignin and hemicellulose thereof. The reaction vessel ( 1 ) has pressurization means for pressurizing to the pressure range, heating means for heating to the temperature range in the state of the pressurization and cooling means for cooling after maintaining of the above state. Multiple reaction vessels ( 1 ) are provided. A pulverization delivery conveyor ( 20 ) is provided superior to these reaction vessels, and each of the multiple reaction vessels is connected via a connection tube ( 4 ) to the conveyor. The connection tube ( 4 ) is provided with pulverizate charging means for charging a given amount of pulverized biomass in accordance with a timing of pulverizate charging to the reaction vessels.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to the field of producingbiocokes using biomass as a raw material, and particularly to a biocokeproducing apparatus and process therefor, which enables industrial massproduction of bio-cokes which can be used particularly as substitutefuel for coal cokes.

2. Description of the Related Art

In recent years, in view of global worming, reduction of CO2 emission ispromoted. Especially, at combustion facilities like power boiler, fossilfuels such as coal and heavy oil are often used as fuel. However, thesefossil fuels are a cause of global warming from a perspective of CO2emission, and thus the use thereof is becoming more regulated in theview of protecting the global environment. Also from a perspective offossil fuel drain, there is a need for developing a substitute energysource and putting the source into practical use.

The effort to promote utilization of fuel using biomass instead of coalcokes is being made. In this invention, biomass is an organic matterattributed to photosynthesis such as ligneous matters, grass plants,crops, and kitchen waste. By processing these types of biomass for fuel,it becomes possible to utilize biomass as an energy source or anindustrial raw material.

The biomass can be transformed into fuel by drying the biomass to fuelor by pressurizing biomass to a fuel pellet, or by carbonization ordestructive distillation. However, in the drying method, air ratio inthe dried biomass remains large and apparent specific gravity is small,thus making it difficult to transport or store the fuel. This form offuel is not very efficient for long distance transportation or storage.

The method to convert biomass into a fuel pellet is disclosed in PatentReference 1 (Japanese Publication S61-27435). This method comprisesadjusting moisture content of comminuted fibrous particles to about 16%to about 28% by weight, and compressing the material in a die to dryinto the fuel pellet.

The method of destructive distillation is disclosed in Patent Reference2 (JP2003-206490A). According to this method, in oxygen-depletedenvironment biomass is heated at 200 to 500° C., preferably 250 to 400°C., thus to produce a precursor of charred compact fuel of biomass.

However, according to the method disclosed in Patent Reference 1,biomass is processed to fuel by pressure-molding, processed fuel palletcontains too much moisture and heat value is low, which is insufficientas fuel.

Moreover, according to a destructive distillation method disclosed inPatent Reference 2 and other references, processed biomass has morevalue than unprocessed biomass but in comparison to coal cokes, stillapparent specific gravity is still small and has lower calorific value.It also has lower hardness compared to coal cokes, which is insufficientto substitute coal cokes.

SUMMARY OF THE INVENTION

The present invention has been made in view of such problems asdescribed above, and it is an object of the present invention to providea biocoke producing apparatus, and process therefor, which enables anefficient mass production of biocokes. In the biocoke producingapparatus and process therefore regarding the present invention, biomassused as a raw material, is an organic matter attributed to,photosynthesis such as ligneous matters, grass plants, crops, andkitchen waste.

Herein, biomass attributed to photosynthesis means all types ofbiomasses which is converted by photosynthesis in sunlight using waterabsorbed from roots and carbon dioxide in the air and forms organicmatters such as sugar, cellulose and lignin.

Recently, as an alternative to coal cokes, recently bio-cokes are beingstudied. Biocokes are produced by maintaining the biomass raw materialin the state of pressurization and heating for a given period of timeand cooling. The pressurization and heating condition of pulverizedbiomass is set within the range inducing thermal decomposition ofhemicellulose or thermal hardening of lignin within the pulverizedbiomass. In this way, reaction mechanism is established and biocoke withhigh hardness and high heat value is produced.

With the reaction mechanism under the above-identified condition,hemicellulose is thermally decomposed and develops adhesion effect, andsuperheated steam from the pulverized biomass induces lignin to react ata low temperature keeping its structure, which acts with consolidationeffect synergistically, thereby producing bio-coke with high hardnessand high heat value. The thermal hardening reaction makes progress asreaction activity spots are induced amongst phenolic macromoleculescontained in lignin or the like.

FIG. 7 is a table comparing physical properties of biocoke with those ofother fuels. The values shown in the table were obtained in experiments,thus should not limit the present invention.

As shown in the table, properties of biocoke are apparent specificgravity 1.2 to 1.38, maximum compressive strength 60 to 200 MPa, heatvalue 18 to 23 MJ/kg, also showing excellence in hardness andcombustibleness, while properties of wood biomass are apparent specificgravity 0.4 to 0.6, maximum compressive strength 30 MPa, heat value 17MJ/kg, also showing inferior performance in hardness and combustiblenessto biocoke. Properties of coal coke are apparent specific gravity 1.85,maximum compressive strength 15, heat value 29 MJ/kg but biocoke stillshows superior performance in combustibleness and hardness.

Consequently, not only biocoke is a functional substitute of coal cokebut also biocoke posses a high value as a material.

However, bio-cokes are still in the experiment stage and in reality thereaction containers are filled up with pulverized biomass manually andmanufactured sequentially using one reaction container.

The present invention proposes A biocoke producing apparatus forproducing biocokes using pulverized biomass raw material attributed tophotosynthesis, by heating and pressure molding the pulverized biomassof which the moisture content is regulated to a given ratio, in reactionvessels in which a temperature range and a pressure range for inducing apyrolytic of hemicellulose and thermal curing reaction of lignin arepreset, the apparatus comprising:

a pressurization means for pressurizing to said pressure range;

a heating means for heating to said temperature range;

a cooling means for cooling after maintaining the state ofpressurization and heating for a given period of time; and

a discharging means for discharging produced biocokes after the cooling,

wherein a plurality of said reaction vessels are provided, apulverization delivery path for conveying the pulverized biomass isprovided superior to the reaction vessels, each of said reaction vesselsbeing connected to said pulverization delivery path via connectiontubes, and said connection tubes are provided with pulverizate chargingmeans for charging a given amount of pulverized biomass in accordancewith a timing of pulverizate charging to the reaction vessels.

According to the present invention, biocokes which can be used tosubstitute for coal cokes, can be efficiently produced. Specifically, byproviding a plurality of reaction vessels, thereby enabling sequentialtreatments and an industrial mass production of biocokes.

Moreover, with the configuration such that the pulverized biomass isconveyed by the pulverizate delivery path, and charged to multiplereaction vessels as needed, large supply units such as a pulverizationunit and a pulverization hopper can be fixedly mounted, and the reactionvessels on a receiving side can be fixedly mounted as well withouthaving to move, thereby simplifying and downsizing the units.

The present invention is also characterized in that at least two ofreaction series having the multiple reaction vessels arranged linearly,and the pulverization delivery path is arranged linearly along thereaction series and the end thereof is connected to the adjacent series,thus to form a circulation circuit.

With the configuration, the multiple reaction vessels are arranged in alinear fashion, and along this, the pulverization delivery path isarranged in a linear fashion, thus an installation area can be smaller,which results in saving space.

Moreover, the pulverization delivery path is preferably a sealed-typepipe conveyor, and with this configuration, pulverizate, even in a formof fluid, can be surely conveyed, and as the conveyor is a sealed-type,pulverizate dispersal is prevented.

Furthermore, the biocoke producing apparatus is characterized in thatthe pulverizate charging means comprises

an upper gate and a lower gate provided in different places in thevertical direction of the connection tube, opening and closing thereofbeing controlled by a control unit in accordance with the timing ofpulverizate charging to the reaction vessels and

position detection sensors arranged between said gates for detecting theamount of the pulverized biomass,

wherein said opening and closing of said upper and lower gates arecontrolled in accordance with said detected amount of the pulverizedbiomass, and a charging amount and charging timing of the pulverizedbiomass into said reaction vessels are regulated.

With the configuration, the charging means for pulverized biomass is adouble gate structure equipped with the position detection sensors, andis configured such that a charging amount of the pulverized biomass isregulated by controlling the opening and closing of the gates inaccordance with the amount of the pulverized biomass detected by theposition detection sensors. Thus, even with this simple configuration, agiven amount of the pulverized biomass can be charged into the reactionvessels at a precise timing.

It is unique in that the pulverizate charging means comprises weightsensors arranged on a bottom of the reaction vessels, charging amountregulation means for regulation the charging amount of the pulverizedbiomass into the reaction vessel in accordance with the amount of thepulverized biomass detected by said weight sensors.

With the configuration that a charging amount of the pulverized biomassis regulated in accordance with the amount of the pulverized biomassdetected by the position detection sensors. Thus, even with this simpleconfiguration, a given amount of the pulverized biomass can be chargedinto the reaction vessels at a precise timing.

It is also characterized in that the reaction vessels(s) is adouble-tube structure creating a cooling/heating media path between aninner tube and an outer tube, said pulverized biomass being charged intosaid inner tube,

said cooling/heating media path is connected to each of a heating mediacircuit for raising the temperature of the heating media and a coolingmedia circuit equipped with a heat exchanger for cooling the coolingmedia with cooling water, and

a cooling tank having enough capacity to cool the cooling media to theboiling point and below is provided in the upstream side of said heatexchanger of said cooling media circuit.

According to the present invention, boiling of the cooling water in thecooling-media heat exchanger is prevented, safe and smooth operationbecomes possible and the minimum amount of the cooling water is neededfor the operation.

As a process invention, process for producing biocokes using pulverizedbiomass raw material attributed to photosynthesis, by heating andpressure molding, in reaction vessels, the pulverized biomass of whichthe moisture content is regulated to a given ratio, wherein

a plurality of said reaction vessels and a pulverizate delivery path fordelivering said pulverized biomass are provided;

a temperature range and a pressure range for inducing a pyrolytic ofhemicellulose and thermal curing reaction of lignin thereof are preset;

said process comprising steps of:

maintaining said pulverized biomass in each of said reaction vessels fora given period of time in a state of pressurization and heating in saidpressure and temperature range;

cooling said pulverized biomass;

treating said pulverized biomass in a series of treatments fordischarging produced biocokes; and

charging a given amount of said pulverized biomass from said pulverizatedelivery path to a corresponding one of said reaction vessels inaccordance with a timing of pulverizate charging to the reaction vesselsin said treating step.

According to this process, the same effects can be obtained as with theaforementioned apparatus invention.

Moreover, heating and pressurizing may be performed simultaneously, orone may start before the other. Specifically, the present inventionincludes all three cases of simultaneously starting both treatments anmaintain the heated and pressurized state, and of starting pressurizingbefore heating and maintaining the state, and of starting heating beforepressurizing and maintaining the state.

Furthermore, the biocoke producing process is characterized in that inthe treating step, the heating is done by supplying heating media tosaid reaction vessels, and cooling is done by supplying cooling media,and at least said heating and cooling among the process steps in themultiple reaction vessels are performed at different timing in each ofsaid reaction vessels.

In this manner, processing steps in the multiple reaction vessels areperformed at different timing in each of the reaction vessels. By makingthe supply timing of the heat media or cooling media different in eachof the reaction vessel, the load on the heating media circuit andcooling media circuit is reduced, downsizing the cooling/heating mediacircuit.

As described above, according to the present invention, it is possibleto efficiently produce in large volume bio-cokes which has high hardnessand heat value and can be used particularly as substitute fuel for coalcokes.

Moreover, with the configuration such that the pulverized biomass isconveyed by the pulverizate delivery path, and charged to multiplereaction vessels as needed, large supply units such as a pulverizationunit and a pulverization hopper can be fixedly mounted, and the reactionvessels on a receiving side can be fixedly mounted as well withouthaving to move, thereby simplifying and downsizing the units.

Furthermore, by configuring the pulverizate charging means with thedouble gate structure or the weight sensors, a simple structure can beachieved and a given amount of the pulverized biomass can be chargedinto the reaction vessels at a precise timing.

It is also configured such that the reaction vessels are heated andcooled by cooling/heating media and provided is the cooling media tankhaving enough capacity to cool the cooling media to the boilingtemperature and below in the upstream of the cooling-media exchanger forsupplying the cooling media, thereby preventing boiling of the coolingwater in the cooling-media heat exchanger and achieving safe and smoothoperation and minimizing the amount of the cooling water needed for theoperation.

By making the supply timing of the heat media or cooling media differentin each of the reaction vessel, the load on the heating media circuitand cooling media circuit is reduced, which enables the cooling/heatingmedia circuit to be downsized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plain view of a biocoke producing apparatus regarding anembodiment of the present invention.

FIG. 2 is a sectional side view of the biocoke producing apparatus shownin FIG. 1.

FIG. 3 is a perspective view showing a pulverizate traveling equipmentof an embodiment.

FIG. 4 is a figure showing an inner structure of the pulverizatetraveling equipment of the embodiment.

FIG. 5 is a sectional side view showing reaction vessels of theembodiment.

FIG. 6 is an equipment system diagram including a circuit ofcooling/heating media of the embodiment.

FIG. 7 is a table comparing physical properties of biocoke.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of the present invention will now be detailedwith reference to the accompanying drawings. It is intended, however,that unless particularly specified, dimensions, materials, relativepositions and so forth of the constituent parts in the embodiments shallbe interpreted as illustrative only not as limitative of the scope ofthe present invention.

FIG. 1 is a plain view of a biocoke producing apparatus regarding anembodiment of the present invention. FIG. 2 is a sectional side view ofthe biocoke producing apparatus shown in FIG. 1. FIG. 3 is a perspectiveview showing a pulverizate traveling equipment of an embodiment. FIG. 4is a figure showing an inner structure of the pulverizate travelingequipment of the embodiment. FIG. 5 is a sectional side view showingreaction vessels of the embodiment. FIG. 6 is an equipment systemdiagram including a circuit of cooling/heating media of the embodiment.

In the present invention, biomass used as raw material for producingbiocoke is organic matter attributed to photosynthesis. The biomass maybe ligneous matters, grass plant, crops, agricultural matters, or thelike. For example, there are instance, examples of biomass includelumber waste, thinned lumber, pruned branches, plants, agriculturalwaste and kitchen waste such as coffee grinds and used tea leaves.

Embodiment

In the embodiment, not only that moisture content of the biomass isadjusted but also that pulverized biomass is used as a raw material,which is biomass pre-treated by being pulverized to a predeterminedparticle diameter or smaller.

The biocoke producing apparatus of the present invention producesbiomass by maintaining pulverized biomass for a certain period of timeafter pressurizing and heating the pulverized biomass under apredetermined condition of pressure and temperature, and then coolingthe pulverized biomass, thereby producing biocokes. The above describedcondition for pressurizing and heating is set within a range thatinduces pyrolytic or thermal curing reaction of hemicellulose and lignincontained in the pulverized biomass. Specifically, pressure andtemperature are set within the range that induces a pyrolytic ofhemicellulose and a thermal curing reaction of lignin contained in thepulverized biomass.

In reference to FIG. 1 and FIG. 2, the overall configuration of thebiocokes producing apparatus of the embodiment is explained.

The biocoke producing apparatus is mainly composed by reaction vessels1, into which pulverized biomass is fed and the aforementioned reactionsare performed so as to produce biocoke, a pulverization deliveryconveyor 20 for conveying the pulverized biomass which is fed to thereaction vessel 1, a conveyor drive unit 21 for driving thepulverization delivery conveyor 20, a pulverizate hopper 22 for feedingthe pulverized biomass, which is pre-treated, to the pulverizationdelivery conveyor 20, and a product conveyor 23 for conveying biocokeproducts discharged from the reaction vessels 1.

There are a plurality of the reaction vessels 1, and the pulverizationdelivery conveyor 20 located superior to the reaction vessels. In theembodiment, two of reaction series having the multiple reaction vessels1 arranged linearly, are provided in parallel, and the pulverizationdelivery conveyor 20 is arranged linearly along the reaction series.Moreover, ends of the pulverization delivery conveyor 20 is connected toadjacent series forming a circuit, and the conveyor drive unit 21 drivesthe conveyor 20 in circle. And on one end side of the pulverizationdelivery conveyor 20, provided is the pulverizate hopper 22 forsupplying and discharging the pulverized biomass of the conveyor 20.

In FIG. 4 and FIG. 5, a specific configuration of the pulverizationdelivery conveyor 20 is shown. In this example of the configuration, aconveyor of sealed pipe-type is used as the pulverization deliveryconveyor 20.

FIG. 4 is a figure showing an inner structure of the conveyor ofpipe-type. This conveyor 20 comprises a cylindrical casing 201, chain202 penetrating through inside of the casing 201, a plurality of blades203 fixed to the chain 202 and provided cross-sectionally and verticalto the axis of the casing 201 as if to penetrate inside of the casing201. In driving the conveyor 20, the chain 202 is moved by means of thedriving unit 21 and along with the movement, the blades 203 move. Thepulverized biomass supplied between the blades 203 is transferred intothe casing 201 as if to be pushed by the blades 203.

As shown in FIG. 4, the pulverization delivery conveyor 20 has a supplypart 21 a for pulverizate and a discharge part 21 b for pulverizateprovided in the location corresponding to the pulverizate hopper 22. Agiven amount of pulverized biomass is supplied into the conveyor at thesupply part 21 a from the pulverization hopper 22, and the remainingpulverized biomass in the conveyor is discharged at the discharge part21 b. By using the pulverization delivery conveyor with thisconfiguration, pulverizate, even in a form of fluid, can be surelyconveyed, and as the conveyor is a sealed-type, dispersal of purverizateis prevented.

Moreover, on the pulverization delivery conveyor 20, openings (not shownin the drawings) for charging the pulverized biomass into the reactionvessels 1, are provided in the location which corresponds to thereaction vessels 1, and each of the multiple reaction vessels 1 isconnected via a connection tube 4 shown in FIG. 2 to the pulverizationdelivery conveyor 20.

In FIG. 5, a detailed configuration of the reaction vessels is shown. Asshown in the drawing, the reaction vessel 1 is equipped with acylindrical reaction cylinder 2 into which the pulverized biomass isfed, the reaction cylinder 2 and the pulverization delivery conveyor 20are connected to the connection tube 4. The connection tube 4 isextendedly provided in the vertical direction, arranged off-centeredfrom the central axis of the reaction cylinder, and a lower part of theconnection tube 4 and an upper opening of the reaction cylinder 2 areconnected with a connection part 7. The upper part of the connectiontube 4 is connected to the pulverization delivery conveyor 20 which areextendedly provided in horizontal direction, the pulverized biomasswhich is conveyed within the pulverization delivery conveyor 20, isarbitrarily supplied into the connection tube 4.

Moreover, the connection tube 4 is equipped with a pulverizate chargingmeans for charging a given amount of the pulverized biomass arbitrarilyinto the reaction cylinder 2. The pulverizate charging means comprisesan upper gate 5A and a lower gate 5B provided in different places in thevertical direction of the connection tube 4, and position detectionsensors 6 a and 6 b arranged between the gates.

The opening and closing of the aforementioned upper gate 5A and lowergate 5B, is controlled by a control unit not shown in the drawing. Theposition detection sensors 6 a and 6 b for detecting an amount of thepulverized biomass are provided between the upper gate 5A and the lowergate 5B. In the embodiment, two of these position detection sensors areprovided in different positions in the vertical direction. However, aslong as the number and location of the sensors enable detection of theamount of the pulverized biomass filled in between the gates, thestructure is not limited to this.

The pulverizate charging means is configured to move in accordance witha timing of pulverizate charging to the reaction vessels 1.Specifically, prior to pressurizing and heating steps in the reactioncylinder 2, first the lower gate 5B is closed and the upper gate 5A isopened, and then the pulverized biomass is let fall from thepulverization delivery conveyor 20 onto the lower gate 5B. Once it isdetected that the pulverizate biomass has accumulated up to the positiondetection sensor 6 a located superior, the upper gate 5A is closed andthe lower gate 5B is released. By doing this, a given amount of thepulverized biomass is charged into the reaction cylinder 2.

Moreover, while the reaction treatment is performed in the reactioncylinder 2, the pulverized biomass can be prepared in the connectiontube 4 as a batch for the next reaction treatment by following theabovementioned process, and as soon as the reaction is completed in thecylinder and the biocoke is discharged, the lower gate 5B is releasedand the pulverized biomass is charged, thereby shortening the operationtime.

Furthermore, as another pulverizate charging means, it is preferable toprovide a weight sensor (not shown) on the bottom of the reaction vessel1. In this case, in accordance with the weight of the pulverized biomassdetected by the weight sensor, a charging amount of the pulverizedbiomass into the reaction vessel 1 is regulated. Regulation of thecharging amount may be done by providing gate(s) between the connectiontubes 4 and the pulverization delivery conveyor 20, then operating theopening and closing thereof.

A pressurization means for pressurizing the pulverized biomass withinthe cylinder 2 to a certain pressure is provided superior to thereaction cylinder 2. The pressurization means comprises a hydrauliccylinder 8 for pressurizing and a pressurization piston 9 reciprocatedby the hydraulic cylinder 8. These parts are aligned concentrically withthe reaction cylinder 2. The pressurization piston 9 is configured as tomaintain the pressurized state for a certain period of time.

Moreover, the reaction cylinder 2 comprises a heating means for heatingcontents to a certain temperature, and a cooling means for cooling afterthe heating step. The heating means and cooling means may be onetemperature regulating means. The embodiment proposes a double-tubestructure as the temperature regulation means which provides jackets onthe reaction cylinder 2. It is configured that a media path 3 forcooling and heating media is created between an inner tube and an outertube. Through the media path 3, heating media or cooling media (hereinafter referred as cooling/heating media) are passed, and heating energyis given to the pulverized biomass filled in the inner tube of thecylinder by means of the cooling/heating media. Located below the mediapath 3 for cooling/heating media is an inlet 3 a for cooling/heatingmedia, and located superior thereto is an outlet 3 b for cooling/heatingmedia. The inlet 3 a and outlet 3 b for cooling/heating media areconnected to a circuit of cooling/heating media which will be describedhereinafter (see FIG. 6).

Furthermore, provided on the bottom of the reaction cylinder 2 is adischarge unit 10 for discharging contents. The discharge unit 10 isconfigured with a bottom lid 11 for sealing a bottom opening of thereaction cylinder 2, a extrusion piston 12 for moving the bottom lid 11in the horizontal direction, and a hydraulic cylinder 13 for driving theextrusion piston. The discharge unit 10 is configured such that afterthe completion of the cooling step in the reaction cylinder 2, theextrusion piston 12 moves the bottom lid 11 and opens the bottom openingof the reaction cylinder so as to let the biocoke in the cylinder 2 fallto be discharged. When discharging the biocoke, the pressurizationpiston 9 may extrude the biocoke from above to let it fall.

The discharged biocokes are loaded on the product conveyor 23 shown inFIG. 1 and FIG. 2, and conveyed. The product conveyor 23 may be arrangeddirectly below the reaction vessels 1, or as proposed in the embodiment,arranged between the two reaction series and the biocokes falling fromthe reaction vessels 1 may be guided onto the product conveyor 23 viaslant planes 24.

The operation of the biocoke producing apparatus with above describedconfiguration is explained including the operation method. Thetemperature, pressure, moisture content, size and others mentionedherein are mere preferable examples of the apparatus and should not beexclusive.

First, for pretreating the pulverized biomass as a raw material,moisture adjustment is performed by drying the biomass to the moisturecontent of 5 to 10%, and the dried biomass is pulverized to 3 mm orsmaller in grain size, preferably 0.1 mm or smaller. Moreover, dependingon types of biomass, moisture conditioning of the biomass may beperformed after the drying and pulverizing steps. By doing so, itbecomes possible to improve density in the reaction cylinder 2 achievingeven filling when the reaction cylinder 2 is filled with the pulverizedbiomass. Thus, contact between pulverized biomass particles is enhancedin a thermal forming, thereby improving a hardness of the formedproduct.

Pulverized biomass is fed into the pulverizate hopper 22. The pulverizedbiomass stored in the hopper 22 is supplied arbitrarily to thepulverization delivery conveyor 20. The pulverized biomass is conveyedas circulating in the pulverization delivery conveyor 20.

Then, a given amount of the pulverized biomass is charged as needed fromthe pulverization delivery conveyor 20 into the reaction vessels 1 viathe connection tube 4. Once the reaction cylinder 2 is filled with thepulverized biomass, the pressurization piston 9 is driven at thehydraulic cylinder 8 for pressurization so as to pressurize and compressthe pulverized biomass within the reaction cylinder 2 to 8 to 25 MPa bythe pressurization piston 9.

Simultaneously, the cooling/heating media are passed through the mediapath 3 for cooling/heating media in the reaction cylinder 2 so as toheat the pulverized biomass in the cylinder 2 to 115 to 230° C. In thisprocess, heating and pressurizing are performed almost simultaneously sothat the inside of the reaction cylinder may be heated in advance beforepressurization, or may be pressurized first before heating.

The above temperature, pressure and moisture content are set in therange which induces pyrolytic or thermal curing reaction ofhemicellulose and lignin contained in the pulverized biomass. In anotherword, it is the range which induces pyrolitic of hemnicellulose andthermal curing reaction of lignin within the pulverized biomass. Themoisture content is set in the range which is sufficient enough to letmoisture create a subcritical state in the cylinder.

The pulverized biomass within the reaction cylinder 2 maintains thestate of the heating and pressurization for a certain period of time.For example, in a case of the cylinder diameter being 50 mm, theretention time is 10 to 20 minutes, and in a case of the cylinderdiameter being 150 mm, the retention time is 30 to 60 minutes.

By performing the reaction under the aforementioned conditions,hemicellulose which is a component of pulverized biomass, is pyrolyzed,developing an adhesion effect; superheated steam developing inside thereaction vessel induces lignin to react at a low temperature whilemaintaining its framework, acting synergistically with a consolidationeffect, thereby producing biocokes with high hardness and high calorificpower. Thermal curing reaction progresses by the induction of reactionactivity points amongst phenolic high-molecules contained in lignin orthe like.

Once completing the reaction, the heating media are drawn out from theheating media path 3 of the reaction cylinder 2, and then the coolingmedia are drawn in. In the embodiment, silicon oil and steam arepreferably used as heating media, and silicon oil, water or air ispreferably used as cooling media. In the state of maintaining thepressurization within the cylinder 2, the biocoke is cooled to 50° C.and below, preferably 40° C. and below by the cooling media. Moreover,if biocokes are taken out at a temperature higher than the aboveidentified temperature, the adhesion effect of hemicellulose decreases.Therefore, biocoke must be cooled before being discharged.

Moreover, after the cooling, the extrusion piston 12 is driven by thehydraulic cylinder 13 for discharging, and the bottom lid 11 of thereaction cylinder 2 is moved to release the bottom of the reactioncylinder 2, and the contents are extruded and discharged from above bythe pressurization piston 9.

The discharged contents make biocoke products and the biocoke productsare conveyed to the product conveyor 23 and retrieved.

With the biocoke producing apparatus and method thereof of the presentinvention, it becomes possible to efficiently produce biocokes with highhardness and high calorific power which can be used as a substitute forcoal cokes. Furthermore, the biocoke produced according to theembodiment can be used as a heat source, reducing agent or the like in acupola furnace or blast furnace for a casting manufacture or an ironmanufacture, and can be used as a burning fuel such as a power boilerfuel and slaked lime, and also as a material utilizing the highcompressive strength of the biocoke.

Basically, according to the embodiment, by providing multiple reactionvessels 1, continuous operation can be done, thus biocokes can beindustrially produced at a large scale.

Moreover, by configuring such that the pulverized biomass is circulatedby the pulverization delivery conveyor 20, and charged to thecorresponding reaction vessels 1 as needed, large supply units such as apulverization unit and the pulverization hopper 22, and multiplereaction vessels 1 at a receiving side can be fixedly mounted, and theunits can be simplified.

Furthermore, the multiple reaction vessels 1 are closely arranged in alinear fashion, and along this, the pulverization delivery conveyor 20is arranged in a linear fashion, thus an installation area can besmaller, which results in saving space.

The charging means for pulverized biomass is a double gate structureequipped with the position detection sensors 6 a and 6 b, and isconfigured such that a charging amount of the pulverized biomass isregulated by controlling the opening and closing of the gates inaccordance with the amount of the pulverized biomass detected by theposition detection sensors. Thus, even with this simple configuration, agiven amount of the pulverized biomass can be charged into the reactionvessels 1 at a precise timing.

In a similar manner, the charging means may be configured such that theweight sensor mounted on the bottom of the reaction cylinder 2 detectsthe weight of the pulverizate and the charging amount is regulated inaccordance with the detected weight. Thus, even with the simpleconfiguration, a given amount of the pulverized biomass can be chargedinto the reaction vessels 1.

Moreover, in the embodiment, it is preferable to provide metal materialswith high heat conductivity on at least one of the top and bottom of thereaction vessels 1. Specifically, metal materials with high heatconductivity are used for the pressurization piston 9 and/or the bottomlid 11. As the metal materials, copper and silver are preferably used.In this case, the materials with high heat conductivity are arranged tobe in contact with the outer circumference of the reaction cylinders 2.

With this, if the diameter of the reaction vessel 1 is large, heatconduction from the outer jacket alone is not enough to transfer heat toinside.

Therefore, by using this configuration, heat energy is transferred notonly from the outer circumference of the reaction cylinder but also fromthe top and bottom, thereby improving heat transfer efficiency,enhancing the reaction of the pulverized biomass and shortening thereaction time. Thus, the units can be downsized.

Next, in reference to FIG. 6, an example of the circuit ofcooling/heating media of the embodiment will be explained below. In thebiocoke producing apparatus of the embodiment, temperature regulationmeans equipped with switching means for switching between heating andcooling in the reaction cylinder 2, is an essential component.Accordingly, by providing the circuit of cooling/heating media as shownin FIG. 6, the temperature regulation means can have high heatconductivity and safety. In the embodiment, an example of using siliconoil for cooling and heating media is explained.

In the present embodiment, each of the inlet 3 a and outlet 3 b forcooling/heating media is connected to the cooling/heating media circuit30. The cooling/heating media circuit 30 is a combined structure of acooling media circuit and a heating media circuit. The inlet 3 b forcooling/heating media is connected to a discharge line 42 forcooling/heating media, splitting into a heating-media return line 42 anda cooling-media return line 43 via a three-way valve 45 on the dischargeline 41.

The heating-media return line 42 is connected to a heating-media tank31. The heating-media tank has a heater 31 a and an agitator 31 b so asto raise the temperature of the cooled heating media. It is preferablethat N₂ gas is supplied from N₂ cylinder as needed and inside of thetank is maintained in an inert atmosphere so as to ensure the safety.The discharge side of the heating-media tank 31 is connected via athree-way valve 46 to a cooling/heating media supply line 40.

With this configuration, the heating-media circuit formed by the heatingmedia tank 31, the cooling/heating media supply line 40, thecooling/heating media path 3 (reaction cylinder 2), and theheating-media return line 42, is configured such that the heating mediaare circulated to the side of the heating media tank 31 by means of thethree-way valves 45 and 46 during the heating of the reaction vessels 1.

The cooling-media return line 43 is connected to a cooling/heating mediaexchanger 36. The cooling media are cooled by heat exchange with coolingwater such as clean water by the cooling/heating media exchanger 36.

Moreover, as a characteristic configuration of the present embodiment, acooling-media tank 35 is provided in the upstream side of thecooling/heating media exchanger 36 on the cooling-media return line 43.The cooling-media tank 35 is capable of cooling lowering the temperatureof the cooling media to at least the boiling point of the water andbelow, preferably 80° C. and below. In the embodiment, the cooling-mediatank 35 has enough cubic capacity to cool to the abovementionedtemperature. It is also preferable that the cooling-media tank 35 isequipped with an agitator 35 a thus to enhance the cooling capacity.

With this configuration, the cooling-media circuit formed by the coolingmedia tank 35, the cooling/heating media exchanger 36, thecooling/heating media supply line 40, the cooling/heating media path 3(reaction cylinder 2), the cooling/heating media discharge line 41, andthe cooling-media return line 43, is configured such that, when coolingthe reaction vessels 1, the three-way valves 45, 46 are switched to theside of the cooling-media tank 35 so as to circulate the cooling mediatoward the cooling-media tank 35.

In the embodiment, since the heating temperature of the reactioncylinder 2 reaches 115 to 230° C., there is a possibility thatcooling/heating media with high temperature are introduced to thecooling media exchanger 36 when switching between cooling and heatingmedia, which causes the cooling water of the cooling media heatexchanger 36 to boil, causing problems such as a breakdown of the units.It is possible to configure the heating-media heat exchanger 36 suchthat the cooling water does not get boiled depending on a designcondition of the heat exchanger 36. However, in that case, the flow rateof the cooling media needs to be increased or the pressurization isneeded, thus it is not efficient.

Therefore, according to the embodiment, by providing the cooling mediatank 35 capable of cooling the cooling media to the boiling temperatureand below, preferably having enough capacity therefor, in the upstreamof the cooling-media exchanger 36, boiling of the cooling water in thecooling-media heat exchanger 36 is prevented, safe and smooth operationbecomes possible and the minimum amount of the cooling water is neededfor the operation.

Moreover, in the embodiment, it is preferable that at least heating stepand cooling step among the process steps in the multiple reactionvessels 1 are performed at different timing in each of the reactionvessels 1. Basically, when performing the heating step in one reactionvessel, the cooling step is performed in another reaction vessel.

By making the supply timing of the heat media or cooling media differentin each of the reaction vessels, the load on the heating media circuitand cooling media circuit is reduced, making the cooling/heating mediacircuit smaller.

INDUSTRIAL APPLICABILITY

By the use of the biocoke producing apparatus and method therefor of theembodiment, it is possible to efficiently produce biocokes with highhardness and high calorific power which can be used to substitute a coalcokes. The biocoke produced according to the embodiment can be used as aheat source, reducing agent or the like in a cupola furnace or blastfurnace for a casting manufacture or an iron manufacture, and also as amaterial utilizing the high compressive strength of the biocoke.

1. A biocoke producing apparatus for producing biocokes using pulverizedbiomass raw material attributed to photosynthesis, by heating andpressure molding the pulverized biomass of which the moisture content isregulated to a given ratio, in reaction vessels in which a temperaturerange and a pressure range for inducing a pyrolytic of hemicellulose andthermal curing reaction of lignin are preset, the apparatus comprising:a pressurization means for pressurizing to said pressure range; aheating means for heating to said temperature range; a cooling means forcooling after maintaining the state of pressurization and heating for agiven period of time; and a discharging means for discharging producedbiocokes after the cooling, wherein a plurality of said reaction vesselsare provided, a pulverization delivery path for conveying the pulverizedbiomass is provided superior to the reaction vessels, each of saidreaction vessels being connected to said pulverization delivery path viaconnection tubes, and said connection tubes are provided withpulverizate charging means for charging a given amount of pulverizedbiomass in accordance with a timing of pulverizate charging to thereaction vessels.
 2. The biocoke producing apparatus according to claim1, wherein at least two of reaction series having the multiple reactionvessels arranged linearly, and the pulverization delivery path isarranged linearly along the reaction series and the end thereof isconnected to the adjacent series, thus to form a circulation circuit. 3.The biocoke producing apparatus according to claim 1, wherein saidpulverizate charging means comprises an upper gate and a lower gateprovided in different places in the vertical direction of the connectiontube, opening and closing thereof being controlled by a control unit inaccordance with the timing of pulverizate charging to the reactionvessels and position detection sensors arranged between said gates fordetecting the amount of the pulverized biomass, wherein said opening andclosing of said upper and lower gates are controlled in accordance withsaid detected amount of the pulverized biomass, and a charging amountand charging timing of the pulverized biomass into said reaction vesselsare regulated.
 4. The biocoke producing apparatus according to claim 1,wherein said pulverizate charging means comprises weight sensorsarranged on a bottom of the reaction vessels, charging amount regulationmeans for regulation the charging amount of the pulverized biomass intothe reaction vessel in accordance with the amount of the pulverizedbiomass detected by said weight sensors.
 5. The biocoke producingapparatus according to claim 1, wherein said reaction vessels(s) is adouble-tube structure creating a cooling/heating media path between aninner tube and an outer tube, said pulverized biomass being charged intosaid inner tube, said cooling/heating media path is connected to each ofa heating media circuit for raising the temperature of the heating mediaand a cooling media circuit equipped with a heat exchanger for coolingthe cooling media with cooling water, and a cooling tank having enoughcapacity to cool the cooling media to the boiling point and below isprovided in the upstream side of said heat exchanger of said coolingmedia circuit.
 6. A process for producing biocokes using pulverizedbiomass raw material attributed to photosynthesis, by heating andpressure molding, in reaction vessels, the pulverized biomass of whichthe moisture content is regulated to a given ratio, wherein a pluralityof said reaction vessels and a pulverizate delivery path for deliveringsaid pulverized biomass are provided; a temperature range and a pressurerange for inducing a pyrolytic of hemicellulose and thermal curingreaction of lignin thereof are preset; said process comprising steps of:maintaining said pulverized biomass in each of said reaction vessels fora given period of time in a state of pressurization and heating in saidpressure and temperature range; cooling said pulverized biomass;treating said pulverized biomass in a series of treatments fordischarging produced biocokes; and charging a given amount of saidpulverized biomass from said pulverizate delivery path to acorresponding one of said reaction vessels in accordance with a timingof pulverizate charging to the reaction vessels in said treating step.7. The process for producing biocokes according to claim 6, wherein insaid treating step, the heating is done by supplying heating media tosaid reaction vessels, and cooling is done by supplying cooling media,and at least said heating and cooling among the process steps in themultiple reaction vessels are performed at different timing in each ofsaid reaction vessels.